How do I use Speech To Text with my Telegram bot in Node-RED?

Hi so I am working in a Telegram bot and I would like to use the Speech To Text Watson option, this is what I have already:

I just need to know what should I put on the function before de file buffer node :

I read in another post that I had to use the file buffer node to convert the audio file from Telegram into a buffer so the Speech To Text node recognise it. Wherever I send a voice message to Telegram I get this on the debut Tab:

I thing I gotta put something similar to this: var files = Object.keys(msg.req.files); msg.payload = msg.req.files[files[0]][0].path; using this probably msg.originalMessage.voice.file_id but really have no ideaaa. Could someone please help me? It is very important and it would be so Great!! Thanks to everyone!!!

Just going by your diagram msg.originalMessage.voice is the most likely location of the audio file, but it only contains a file_id. This implies that the audio has been saved as a file, but where? You need to check the documentation for the Telegram Node to work out where and subsequently how to load it.